Subject testing for the final study of the project has been completed. This study examined the effects of haloperidol on facial, oral and vocal tics and language processing deficits in monozygotic twins with Tourette Syndrome and attention deficit disorder. The purpose was to determine: 1) whether the response to haloperidol was beneficial in these patients with Tourette Syndrome with attention deficit disorder; 2) whether haloperidol benefited the language processing and attentional deficits in these patients; and 3) whether a similar type and degree of response to haloperidol was found in both twins. The final stages of analysis of video tapes, language tests and auditory vigilance tests are close to completion.